1. Field of the Invention
The present invention is directed to a device to measure the vertical jump height of an athlete. In particular, the present invention is directed to a jump height vertical measuring device which will compute the time period that the jumper's feet are off the floor during a jump and convert that time period to a vertical jump height measurement.
2. Prior Art
Measuring the vertical jump height of an athlete is a test performed by athletic coaches and evaluators around the world. It tells how much power the athlete can exert from his or her legs and also gives a general idea about the jumping potential of the athlete. While vertical jump height is most often associated with the sport of basketball, it is also pertinent to other sports, such as football.
In the past, one method of measuring vertical jump height involved a large movable frame having a series of shims extending from the frame side. The athlete would zero the fixture to his or her body and then knock away as many shims as possible while jumping. The knocked-away shims would indicate the vertical jump of the athlete. This procedure would be prone to cheating if the zeroing phase were not accurate. Additionally, the fixture was typically not portable. Additionally, oftentimes the height indication would be 8 to 12 feet above floor level and, therefore, not conveniently observed.
Additionally, in the past, a shoe has been modified as shown in Cherdak (U.S. Pat. Nos. 5,343,445; 5,452,269) to include a timer device within the shoe. The timer device would measure the "hang time" and not the vertical jumping height. Moreover, the timing device is a part of and within the athletic shoe and is not conducive to testing many athletes quickly.
Various other timing devices are well known, such as swim racing timers. One example is shown in Tenaka(SP) (U.S. Pat. No. 5,349,569).
It is known that when an object is set into vertical upward motion, its position can be described using Newtonian physics. Mathematical relations may be derived to relate the maximum height the object reaches and the time of the motion. These equations may be simple or complex, depending upon the assumptions made during their derivation (wind resistance, local distance to earth's center, stiffness of shoes, etc.). Moreover, empirical relations may be established between time of motion and jump height by observing data from experiments where jump height and time are both measured and plotted against each other.
By measuring the total time period of the jump, a vertical jump height can be derived.
It is, therefore, an object and purpose of the present invention to provide a portable or heavy-duty, vertical jump measuring device which will measure the vertical jump height of a jumper.
It is a further object and purpose of the present invention to provide a portable or heavy-duty, vertical jump measuring device which will calculate the time period of a jump and convert the time period into a vertical jump height measuring.
It is a further object and purpose of the present invention to provide a vertical jump measuring device which is portable and lightweight.
It is a further object and purpose of the present invention to provide a vertical jump measuring device that may be used to obtain measurements quickly and thereafter to reset for additional measurements.
It is a further object and purpose of the present invention to measure the force of the jumper upon take-off and landing as well as the time period of the jump and convert those measurements into vertical jump height.